Bioeconomic Model of Fishery Resources Under Ecological and Technological Interdependencies

In the last chapter, we introduced the bioeconomic allocation model and theory of single fishery species under the same fishing fleet. However, any kind of fish population can not survive in the water alone, and inevitably interact with other populations to form an interdependent and interrelated marine ecosystem. Therefore, it must be assumed that the mutual influence of interspecific relationship is ignored to describe the dynamic with single population allocation model using by single differential equation or difference equation, which is more reasonable only when a fishery resource is in the low-level fishing development. Nowadays, fishery resources are widely exploited and utilized, the low-level fishing development is less and less. Due to the increasing fishing intensity, the sharp changes in the resources of target and nontarget species and the changes in species composition in the development groups have been noticed all over the world. At the same time, due to overfishing, the resources of high-value species at the higher level of the food chain are further reduced. In this way, we realize that due to different fishing efforts and different fishing gear direct or indirect fishing, they will affect many kinds of resources. In recent decades, fishery scientists have begun to use the holistic analysis method to manage fishery. In addition to considering the influence of generations within the population, they should also consider the interaction of biological ecology and technology. Therefore, the optimal allocation of fishery resources development and utilization not only needs to consider the influence between generations but also involves interspecies and technical issues. This chapter mainly focuses on the bioeconomic balance model and optimal allocation of two kinds of fish to illustrate the basic methods of optimal allocation of multispecies resources.